CPI Outlet Test Plan

Consumer Expenditure Survey/Outlets Test Plan
Proposed for 2011, Second Quarter
8/3/10
Background
Recently, the Telephone Point of Purchase Survey (TPOPS) has been criticized
because of its design. It’s an RDD landline only survey. Coverage bias may
exist because the TPOPS does not contact cell-phone-only households. Because
the CE Survey is personal visit, it contacts landline and cell phone cohorts. An
analysis of the types of stores or retail outlets reported by both cohorts in the
CE would begin to determine if the TPOPS truly has a bias associated with its
frame.
Test objectives
1. To collect outlet information on broad categories of items for all CE
respondents
2. To compare the outlets and types of outlets reported by cell phone only
households against non-cell phone only households at the national level
3. To evaluate differences reported by the two cohorts
Hypothesis
Outlets and outlet types do not differ between cell phone only and a second
group consisting of landline only households and households that have both
landlines and cell phones.
Study Design
Sample: The CE Interview Survey obtains approximately 7000 completed
interviews each quarter. At the end of the survey, outlet questions for 5 broad
categories of expenditures will be asked. These categories are:
1.
2.
3.
4.
5.

Groceries
Clothing
Music
Meals at Restaurants
Electronics

For each category, the respondent will be asked (i) the name of the store in
which the last purchase for that category was made and (ii) what type of outlet
it was: brick and mortar, internet, phone/catalog and other.

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Group assignment: The households will be separated into three cohorts: 1. cell
phone only, 2. Landline only and both landline and cell phones, and 3. No phone
expenditures. These cohorts will be assigned using type of phone bills reported
in Section 4 of the CE Interview Survey as a proxy for household phone usage.
The breakdown of data from 2009:
Cell phone only:
30%
Landline/Both LL and Cell
60%
No phone bills
10%
Design:
We are expecting close to 100% response for four of the five categories to be
tested, because we are not asking about purchases within a set time frame. We
are asking for the last purchase. For each category, we’re expecting
approximately 2,100 responses for the cell phone only cohort and 4,200
responses for the remaining cases (households with phone service other than
cell phone only).
For the Music category, the expected number of responses might be lower
because there is a larger expectation of no purchases or don’t know. Even if
this results in a 50% decrease in the values, over 1,000 observations are
expected for the cell phone only cohort.
Analysis:
When the data are received, a manual coding process will assign a unique code
to each unique outlet name, and a series of bimodal classifications will be made
based upon outlet attribute data obtained from secondary sources (e.g., Large
national franchise and Other). For each classification, the differences between
the two groups of households will be evaluated using a chi-squared test and
other statistical inference tests, with the null hypothesis of no difference
between the two groups.
Comparisons will also be made on the type of outlets reported for each category
by cohort with the null hypothesis of no difference between the two groups.
Post-study results:
Study implementation
‐ Issues found/occurred during testing
‐ Interim results
Results
‐ Final sample composition
‐ Final group composition
‐ Key results
Conclusions
‐ Implications of findings
‐ Next steps

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Proposed CEQ Questions for CPI Outlets Test 

This new section of outlet questions should have its own tab following the last section in the interview 
(for example, it would follow section 20 in interview 1 or would follow section 22 in interview 2).  These 
questions will not be required for a complete interview. 

Number  Variable Name 
Question 
1 
LDLNPHON 
Do you/your household currently have at least one phone inside 

your home that is currently working and is not a cell phone? 
1. Yes 
2. No 
3. Don’t know 

2 

POP_INTRO 

3 

ELECPOP 

4 

PURELEC 

5 

MUSICPOP 

Allow RF 

<1, 2, 3, RF> go to POP_INTRO 
Now I have a few questions about where  last shopped for select items. For the following 
categories, please tell me the name of the store, business, or 
website that you or anyone in your household last made a 
purchase and whether the purchase was made by personal visit to 
the store, online, by catalog or phone order, or by another 
method. 
1. Continue 

<1> go to ELECPOP 
Where did you last purchase electronics? 

Allow DK, RF 

< 30 char, DK, RF> go to PURELEC 
Was that purchase made by personal visit, online, phone/catalog 
or some other way? 
1. Personal visit 
2. Internet purchase 
3. Phone or catalog purchase 
4. Another method 

Allow DK, RF 

<1‐4, DK, RF> go to MUSICPOP 
Where did you last purchase music? 

Allow DK, RF 
3 

6 

PURMUSIC 

7 

CLOTHPOP 

8 

PURCLOTH 

9 

RESTPOP 

10 

PURREST 

11 

GROCPOP 

<30 char, DK, RF> go to PURMUSIC 
Was that purchase made by personal visit, online, phone/catalog 
or some other way? 
1. Personal visit 
2. Internet purchase 
3. Phone or catalog purchase 
4. Another method 

Allow DK, RF 

<1‐4, DK, RF> go to CLOTHPOP 
Where did you last purchase clothing? 

Allow DK, RF 

<30 char, DK, RF> go to PURCLOTH 
Was that purchase made by personal visit, online, phone/catalog 
or some other way? 
1. Personal visit 
2. Internet purchase 
3. Phone or catalog purchase 
4. Another method 

Allow DK, RF 

<1‐4, DK, RF> go to RESTPOP 
Where did you last make a restaurant purchase? 

Allow DK, RF 

<30 char, DK, RF> go to PURREST 
Was that purchase made by personal visit, online, phone/catalog 
or some other way? 
1. Personal visit 
2. Internet purchase 
3. Phone or catalog purchase 
4. Another method 

Allow DK, RF 

<1‐4, DK, RF> go to GROCPOP 
Where did you last purchase groceries? 
4 

12 

PURGROC 

Allow DK, RF 

<30 char, DK, RF> go to PURGROC 
Was that purchase made by personal visit, online, phone/catalog 
or some other way?  
1. Personal visit 
2. Internet purchase 
3. Phone or catalog purchase 
4. Another method 

Allow DK, RF 

<1‐4, DK, RF> go to END POP block/go to BACK section 

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